The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 25, 1979
Filed:
May. 22, 1978
John J Ward, Wantage, GB;
Clive Barnes, Wantage, GB;
BNF Metals Technology Centre, Oxon, GB;
Abstract
A method of depositing a protective chromite conversion coating is described. The chromite coatings produced by the method contain no Cr.sup.VI. The electrolyte used in the method comprises Cr.sup.III ions in a concentration of not more than 1 molar and a weak complexing agent for Cr.sup.III ions. The electrolyte, preferably, also contains conductivity salts. The method involves using a cathode current density of not more than 2000 amps per square meter and a temperature of not more than 35.degree. C. for a period of not more than 3 minutes. The chromite conversion coatings can be improved by aging and can be subsequently painted or lacquered. The Cr.sup.III electrolytes used are much less corrosive than Cr.sup.VI electrolytes and thus the substrates which can be coated include materials which cannot readily be chromate coated because they are reactive towards Cr.sup.VI electrolytes.